1. Field of the Invention
The subject invention relates to adjuvants for postemergent herbicides, which fall into the category of crop oil concentrates. More particularly, the subject invention relates to improved crop oil concentrates which enhance the efficacy of herbicides, allowing greater or equal weed control while using less active ingredient.
2. Description of the Related Art
It is well established that a variety of adjuvants play important roles in the application of herbicides. These adjuvants are a diverse group of components with equally diverse functions which may often be determined from their generic names, i.e. "spreaders," "stickers," "solubilizers," "emulsifiers," "flow control agents," "drift control agents," and so on. Among the many useful herbicide adjuvants are the so-called "crop oil concentrates."
Crop oil concentrates are often recommended by herbicide manufacturers and formulators for inclusion in tank mixes to increase the efficacy of postemergent herbicide formulations. Crop oil concentrates are available from a variety of sources, and generally consist of from 75-95 percent by weight of a hydrocarbon oil or solvent with the balance being a surfactant, although in certain cases the surfactant may comprise a majority of the composition, or even all of the composition.
The hydrocarbons which form a major part of the crop oil concentrate may be derived from mineral (petroleum) or vegetable sources. When derived from mineral sources, the hydrocarbon component may be predominately paraffinic, or may be aromatic, particularly alkylated aromatic.
Although the use of selected crop oil concentrates may enhance herbicidal efficacy, it is well known that many of the proprietary concentrates available are not as effective as others. Some may even impact negatively upon herbicidal efficacy. Additionally, there is a great deal of inconsistency with regard to the make up of available crop oil concentrates. Finally, to further complicate the situation, manufacturers frequently change the formulations without notifying the consumer, resulting in a great deal of uncertainty with regard to their performance.
In recent years, the situation with respect to crop oil concentrates has achieved such a level of notoriety that some agriculturists refer to them as "snake oils." Thus there is a need in the agricultural sector, for a crop oil concentrate with a well defined make-up which is capable of enhancing the efficacy of a broad spectrum of herbicides, and which gives reproducible results.